This patent application is directed to an invention comprising a liquid fuel composition containing additive amounts of polymer supported amino alcohols. These novel additives improve the flow properties of such fuels.
Traditionally, the low-temperature properties of distillate fuels have been improved by the addition of kerosene, sometimes in very large amounts (5-70 wt %). The kerosene dilutes the wax in the fuel, i.e., lowers the overall weight fraction of wax, and thereby lowers the cloud point. The additives of this invention effectively lower the cloud point of distillate fuel without any appreciable dilution of the wax component.
Other additives known in the art have been used in lieu of kerosene to improve the low-temperature properties of distillate fuels. Many such additives are polymeric materials with pendent fatty hydrocarbon groups, and are usually derived from the free radical polymerization of unsaturated hydrocarbons (olefins, acrylates, fumarates, etc.). These additives are limited in their range of activity, however; most improve fuel properties by lowering the pour point and/or filterability temperature. These same additives have little or no effect on the cloud point of the fuel.
Many additives for reducing the pour point and/or filterability temperature are known which are derived from free radical polymerization of carbon-carbon double bond containing compounds. These new additives are distinct from those known in that the new additives are effective in lowering the cloud point of diesel fuels but are not effective in lowering the pour point of diesel fuels. Thus these new additives are unique in their function to improve the low-temperature flow properties of such fuels. These compounds are structurally different from other compounds known to lower the cloud point of distillate fuels, especially in that the amino alcohol is supported on a polymer.
The new additives incorporate, for example, a 1-alkyl-N,N-dialkyl ethanolamine into the preformed polymer. Pour point additives are not known to possess this type moiety. Thus these new additives are unique in chemical composition.